Hydraulic device for oil well pumping



Jan. 7, 1936. M. KAHR ET AL HYDRAULEEC DEVICE FOR OIL WELL PUMPING Filed June 29, 1931 8 Sheets-sheaf. l

M. KAHR ET AL 2,027,104

HYDRAULIC DEVICE FOR OIL WELL PUMPING Jan. 7,19%.

8 Sheets-Sheet 2 Filed June 29, 1931 Jan. 7, 1936; I M. KAHR ET AL' 2,027,104

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M. KAHR El AL HYDRAULIC DEVICE FOR OIL WELL PUMPING Jan. 7, 1936;

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' HYIDRAULIG DEVICE FOR OIL W LL PUMPING Filed June 29, 1931 8 Sheets-Sheet 5 I p n Jan. 7,1936. M. KAHR El AL HYDRAULIC DEVICE FOR OIL WELL PUMPING a Sheets-Shet 6 Filed June 29, 1931 WNW N @v Q wuw rrr 8 Sheets-Sheet '7 I I IIIIIIIIIIA'IIIII /IIII/III I M. KAHR ET AL HYDRAULIC DEVICE FOR OIL WELL PUMPING Filed June 29, 1951 Jan. 7, 1936.

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HYDRAULIC DEVICE FOR OIL WELL PUMPING Filed June 29, 1931 s sheet -sheets 9 W 9 "(IN-'1! "w s 11 0 i T/ME IN SECONDS DIAGRAM Patented Jan. 7, 1936 UNITED STATES HYDRAULIC DEVICE FOR OIL WELL PUMPING Martin Kahr am John s. Kahr, Milwaukee, was; said John S. Kahr assignor to said Martin Kahr Application June 29, 1931, Serial No. 547,482

37 Claims. The present invention relates to oil well pumping devices and more in particularto ahydraulic means and mechanism for pumping oil wells whereby the operation may be accomplished with i 5 greater facility and at less expense and the unit is capable of pumping deeper wells than is possible with the. devices. now in use. These latter I devices are mechanically operated, and include apparatus using a crank movement in combinal tion with connecting rod and so-called walkin beam. In these prior constructions great difficulty is encountered in pumping wells of any considerable depth. The main difficulties encountered-are that the load on the pumping rod is so 15 great that the rod frequently breaks, causing shut-downs, repairs, and in most casesloss of product. Increasing the size of the rod in order to take care of the great load in such wells, would not eliminate this diiiiculty for the reason that any increased size of the rod would necessarily increase the load.

Three forces combine to cause the enormous strain on the rod, and these items are (1)- the weight of the pumping rod itself; (2) the weight of the oil to be lifted; and (3) the force required to accelerate the combined mass of rod and oil from a zero velocity to a certain maximum'velocity. The.,third item is quite high when the common mechanical devices are employed; i; e.,

W apparatus using crank movement in combination with connecting rod and the so-called walking beam. The reason for the great strain imparted to the pump rod is very evident when the elongation of the pump rod is considered. We

device employing the crank movement, when the plunger of the pump in the bottom of the well is inits'lowest position. The rod has an elongation dueto its own weight which is constant dur- 9 ing the whole cycle.

Before the oil starts its upward movement, a force equal to the weight of the oil acting on the plunger is imposed on the pump rod. This force causes a considerable additional elongation in the rod.

' Thus before the oil has started to move upwards the crank is very far on its way from the starting position, that is its upperdead center 0 and the rod is very near its maximum. At this point in the cycle the whole volume of oil has tobe accelerated from a stand-still. -Due to the high velocity of the pump rod at this point in the cycle observe for instance the working of apumping velocity of the upper end of the pump the force required for the acceleration of the .911

is very high and the rod is subjected to an extremely high tension strain.

The present hydraulic mechanism or unit for oil well pumping and particularly deep well pumping, has the highly important function and feature of decreasing the acceleration forces, and consequently the stress on the pump rod, to a minimum. This is efiiciently accomplished by imparting to the pump rod such a motion that in the point of the cycle when the oil shall be lifted 10 the velocity of the rod is very low or zero, and from this point employing a slow and uniform acceleration of the rod up to the maximum velocity and thereafter let the rod rapidly decelerate to 'a standstill. In combination herewith we employ a much longer duration for the upstroke than for the downstroke, which latter commences with a rapid acceleration up to a maximum velocity and ends with a slow deceleration. The duration of each period within the cycle is dependent on the depth of the well, size and weight of pump rod and weight of oil to be lifted, etc., wherefore it is of utmost importance that the device is of such 'design that to the pump rod can be imparted any predetermined positive cyclic movement. The most favorable cycle can be calculated for each different case and the contour of the control'cam given a corresponding shape.

Among the objects of the present invention is to provide a novel means and method of hydraulic 3 power transmission, and more in particular for pumping oil wells by the employment of hydraulic equipment whereby the upstroke, when the oil is being lifted, has a selective longer duration than the downstroke.

cam arrangement in'combination with a variable capacity pump whereby, on the working stroke, there is provided a very slow and uniform acceleration up to a maximum velocity, after which the piston inthe pumping cylinder decelerates rapidly to a stand-still or zero position. Then the suction or return stroke commences withthe rapid acceleration and ends with a very slow deceleration, thus causing very. little strain on the pump rod. By this means and method the stress in the pump or operating rod is reduced to a minimum.

A further object of the invention is to providea means and method of oil well pumping whereby .the stroke of the operating mechanism may be varied at will during operation so as to give any desired stroke to the pumping rod. By the em--' ployment of the present hydraulic system or hydraulic pumping equipment or unit, it is possible to hydraulically operate a piston for pumping oil from an extremely deep sunk well. The piston The invention contemplates a 5 pump is so operated as to be given an upstroke of selective longer duration than the downstroke whereby to efiiciently pump the oil from the well, and at the same time reduce the danger of breakage of the pump rod.

A further object is to provide an hydraulic power transmission system including a cylinder provided. with a reciprocating piston actuated by fluid delivered thereto, with means for controlling the delivered fluid for the purpose of imparting to the piston any desired predetermined cyclic movement. The invention comprehends the employment of a variable capacity and reversible discharge pump. The present construction although disclosed as adapted for use in oil well pumping equipment, is equally well adapted for use on any machine or device where a positive automatic cyclic movement is desired, as in presses, planers, milling machines, rolling mills, or in any machine where useful work is accomplished during a part of the cycle. Another objectis the provision of a novel controlling means for an hydraulic or fluid pump whereby fluid delivered by the pump may operate a piston pump in a desired predetermined cyclic movement.

Another object of the invention is the provision of a cylinder and a reciprocating piston in an hydraulic device, and means for operating the piston in synchronism with the flow of fluid delivered from an hydraulic pump. Still another object is the provision of the cylinder with means for preventing the cylinder from being overcharged. The invention comprehends .a supply and a by-pass at each end of the cylinder so as to by-pass any excess charge which would overcharge the cylinder with fluid on either side of the piston.

A further object is to provide means in the cylinder for checking the piston so as to prevent .too sudden stops in the movement of the piston, or shocks imposed thereon. Still another'object is the provision of means for adjusting the position of the piston in relation tothe pump rod through which the power from the piston is transmitted. The invention further comprehends the provision of means for locking the piston to the pump rod whereby to prevent relative turning and shifting in relation to one another.

A further object is to provide an hydraulic pumping unit which can conveniently and efiiciently be applied to the varied conditionswhich have-to be met in oil well pumping. .By reason of the present means and method, and the desired predetermined movement of the pump plunger, production can be increased to a maximum. To attain this desired or required plungenmovement, the control cam is given a desired contour or shape.

Still another object is the provision of a novel cam construction in a controlling mechanism for an hydraulic pump whereby a piston operated by the pump may be given any desired predetermined cyclic movement.

A still further object is to provide a novel mechanism for controlling the stroke of the pump. The invention contemplates the provision of a va .riable capacity and reversible discharge pump adapted to operate a piston forpumping the oil, the stroke being readily altered by a control mechanism.

Another object is the provision of a novel means and method of varying the stroke of the control device whereby the same can be adjusted readily while the pump is operating from a zero p0sitionto a position of maximum stroke.'- By the use of the controlling mechanism for a variable capacity hydraulic pump, the capacity of the pump may be varied from themaximum to a minimum position without interrupting or in any way interferingwith its operation. 5

Still another object is the provision of the balancing cylinder construction employed in combination with the hydraulic pump to balance such part of the reactive forces inside the pump which increase or decrease with the hydraulic pressure 1 in the system. Another object is the provision of a stroke limiting device preventing accumulation of error in the control cylinder by reason of any inaccuracy in the cam within the stroke controlling device, for controlling the input and output 1 of the variable capacity pump.

This stroke limiting device corrects any error in the control cylinder at each cycle. The stroke limiting device limits the stroke of the control piston in the control cylinder, the control cylin- 2 der taking care of or providing the force required to shift the floating ring of the variable capacity pump ofi center against the high pressure and resistance in the pump.

Another object is the provision of a novel means 2 and method for controlling the stroke and operation of the pump. The present construction provides either mechanical or hydraulic means for performing this function, the hydraulic means including a servo or auxiliary pump or unit rotating 3 I 'in timed and synchronized relation with the main pump.

Further objects are to provide a construction of maximum simplicity, efficiency, economy and ease of assembly, operation, repair and main- 8 tenance; and such further objects, advantages and capabilities as will later more fully appear, and as are inherently possessed thereby.

The invention further resides in the combination, construction and arrangements of parts illustrated in theaccompanying drawings, and while there is shown therein a preferred embodiment, it is to be understood that the same is susceptible of modification and change, and comprehends other details, arrangements of parts, 4 features and constructions, without departing from the spirit of the invention.

Referring to the drawings:

Fig. 1 is a view in side elevation of the oil well pumping unit.

Fig. 2 is a plan view of the unit disclosed in Fig. 1.

Fig. 3 is an enlarged view in side elevation of the pump and controlling mechanism shown in Figs. 1 and 2, but disclosing these constructions o in rearranged position.

Fig. 4 is a plan view of the constructions shown in Fig. 3.

Fig. 5 is a view in vertical cross section taken 6 through the stroke controlling device.

' tion disclosed in Fig. 8.

Fig. 10 is a view in horizontal cross section taken through the variable capacity pump.

.Fig. 11 is a view in vertical cross section taken through the variable capacity pump, and disclos- Y 2,027,104 r f 3 ing the floating ring in the pump in maximum 4 ofi-center position to the left.

Fig. 12 is a view similar to Fig. 11 but disclosfingthe floating ring in maximum off-center position to the right.

Figs. 13, 14 and 15 arefragmentary, discon- 'nected views, part in side elevation "and part in verticalcross section, of the details of the pumping cylinder, piston and pump rod.

Fig. 16 is a view, part in side elevation and part in vertical cross section disclosing a modification of the hydraulic equipment.

Fig. 1'7 is a view, part in sideelevation and part in vertical cross section disclosing a modification of the hydraulic equipment with the controlling mechanism reversed.

Fig. 18 is a view in horizontal cross section taken on the line l8-i 8 of Fig. 1'7.

Fig. 19 is a top plan view of the hydraulic unit for operating the piston in the pumping cylinder.

Fig. 20 is a typical time-delivery. and piston acceleration diagram or chart indicating the movement of the piston in the cylinder.

Fig. 21is a fragmentary view-of a relief valve.

Fig. 22 is a fragmentary view of a replenishing valve.

Referring more particularly to the disclosure in the drawings, and more especially to Figs. 1 and 2, the pumping installation, disclosed somewhat diagrammatically, includes an engine orpower plant I of any well known type adapted to drive, through the medium of a pulley 2, a belt 3, driving a pulley 4 on a shaft 5. The pulleys and shaft 5 in turn rotate a pulley 6 for driving a belt 1. This belt I in. turn drives a pulley wheel 8,. the latter driving the shaft 9 of the variable capacity and reversible discharge pump Ill. The means for driving the pump I0 is but illustrative, and it is to be understood that any well known drive mechanism and change speed arrangement such as pulleys, gears direct to the shaft of an electric motor, or the like, may be employed. Conduits H and 12 are connectedto the pump l0 and from I there to the motor cylinder 13, the conduit being connected to the cylinder by means of a manifold M, while the conduit 12 is connected to the cylinder by meansof a manifold l5.

The cylinder I3 is supplied with fluid under pressure by means of the variable capacity, reversible discharge'fluid pump 10, which is continuously driven by a gas or oil engine, or other prime mover or power plant I through the medium of a belt or chain drive, as explained above,

v 'or by electric motor direct connected to the shaft 9. This pump is of the variable stroke type, and it may obviously be of any desired or suitable construction, which permits the reversal of the direction of the fluid circulated by it, while the driving motor or prime mover always operates inthe same direction. For alteringthe stroke of the supply pump 10 and hence. theamount and direction of the flow delivered from it, the invention comprehends a control mechanism whereby the stroke of the supply pump may be varied at will. This control mechanism comprises a structure enclosed within the housing 16 for securing the desired'acceleration and deceleration on the pistonwithinthe cylinder I3, in every instant-of the stroke during the cycle, and a control device within the housing l1 for controlling the length of thestroke of the piston in the motor cylinder l3 accomplished by varying the capacity and direction of flow from the pump l0.

In order to control the acceleration and deceleration on the piston .within .the pumping cylinder through a speed reducer l8 by means of a sprocket l3 and chain 2ll'from the shaft ofthe pump l0, so that the pump I 0 and shaft iii are rotated intermediate bearing blocks 23 and supporting guides 24. These guides are provided with end plates 25 and 26, the end plates and guides being assembled with bolts or the like 21. Each.

end plate is provided with a pin or shaft 28, upon which is rotatably mounted a roller 29, adapted to. be held in seating engagement with the face or circumference of the cam. The guides 24 are adapted to slide on the bearing blocks 23, so that when the cam rotates the guides 24 and their end plates will shift horizontally, the shaft l8 and bearing blocks 23 of course being prevented from shifting.

Connected to the end plate 26 0f the guides 24, is a connecting or lever rod 3| which at its forward end 3l Fig. 7,.is bifurcated to receive the end of a lever 32. This lever 32 at its lower portion is enlarged to provide an internal guideway 33 and external guides 34, the latter adapt- -ed to receivecross heads 35 which are adapted to slide within the guides. The cross heads 35 are pivotally mounted upon pins 36 provided on a fork 31, the fork being provided with side members 38 adapted to span the lever 32 and.

its enlarged head 32. The pins 36 provide a fulcrum about which the lever 32 oscillates, the

position of this fulcrum determining the stroke .Of the pump 10.

Mounted'within the internal guideway' 33 of the lever 32 is a block 39 pivotally mounted at 40 within the side walls or web 4| of the enlarged head 32 of thelever. This block 39 may rotate within the lever, but by reason of the pivotal mounting 40, is shiftable therewith so that any oscillation of the lever 32 is transmitted to the block 39, which in turn transmits this motion to the horizontally extending rod 42 which in turn transmits its movement to the floating of the rod 42, which in turn controls the length -of the stroke of the piston in the cylinder 13 and also controls the capacity of the flow of the. fluid from the pump in in both directions, the fork 31 is provided'with an adjusting screw 45 adapted to be operated bymeans of a hand wheel 46'.

When the hand wheel is operated to raise the fork 31 to its. uppermost position, the fulcrum- 36 is at its uppermost position on the lever 32,

and the lever 32 will transmit a maximum reciprocation orstroke to therod 42. When the fulcrum or pins 36 on the fork 3'I,.Fig. 7, is at 1 its lowermost position, which is adjacent the pivot.4!l of the block 39, no reciprocation or longitudinal movement is transmitted to the rod 42 and thus the stroke of the pump is at a minimum or zero. Thus the hand wheel 45 permitsadjustment of the fulcrum on the fork 31, which in turn adjusts the stroke of the pump I! from zero to maximum stroke. When the desired stroke is obtained, the adiusting'screw 45 may be locked. This is accomplished by making the cover or closure 41, Fig. 3. split and provided with a lock screw 480. This adjustment of the stroke of the pump may be accomplished durl3, Figs. 3 and 4, a shaft I8 is driven ing the operation of the pump whereby to eliminateany shut-downs or delay. In Figs. 8 and 9 is disclosed an alternate construction of cam mechanism.

In this construction the shaft i8 is provided with a pair of earns 48 and 49. A'sliding guide 50 provided with end plates and 52 held totion disclosed in Fig. 5, the cam members 48 and 49 are so formed as to give to the sliding guide member 50 a reciprocatory motion to obtain the desired acceleration and deceleration of I the piston in the cylinder i3.

The cam through its levers and the rod 42 transmits the longitudinal reciprocating motion through a coupling 58 to the control or cross bar 59 on the supply pump 10. The supply pump will then deliver a flow of fluid under pressure first in one direction and then in the other,

. through the conduits I hand i2. The pump comprises a body 60, Fig. 11, provided with a series of radial cylinders, the number and size of which vary with the capacity of the pump. The cylinder body 60 is mounted on ball bearings seated in the covers of the pump. Fastened to one end 'of the body 60 and extending out through the cover 62, Fig. 10, is the spindle or shaft 9 by means of which the pump is rotated by the prime mover. Fixed in the opposite cover 63 is a non-rotatable shaft provided with intake and discharge ports 64, Figs. 11 and 12, communicating with the conduits ii and i2.

It is through these ports 66 that the fluid is drawn into the pump and discharged from it. In each radial cylinder is a plunger 65 with a gudgeon pin 66 fastened to its outer end. This pin engages in slippers 61, one on each side of the plunger, the slippers fitting in circular grooves which encircle the cylindrical body. Around the ;body 60 isprovided a. floating ring 68, Fig. 10.

This floating ring 68 is mounted on ball bearings 59 seated in guide blocks on each end, the ring and guide block assembly being supported on guides on the two end covers. This arrangement allows the floating ring with the circular grooves in which the slippers are engaged to be moved at will so that it is on-center with reference to the cylinder body, or off-center to either side. This arrangement gives the stroke to the pump and controls the amount of stroke and the volume and direction of discharge.

In Fig. 11 the floating ring is disclosed as chcenter to the left of the cylinder body, the cylinderv body being rotated by the prime mover in the direction indicated by the arrow, and continuously and at' a constant speed about the shaft which contains the ports 54 and which carries the plungers and slippers around with it. As

. shown during the upper half of each revolution,

the plungers are forced inward by the slippers,

following the races in the floating ring and producing the discharge stroke of the pump, while during the lower half they are drawn outward, producing the suction stroke..

When the floating ring is off-center to the right of the cylinder body as disclosed in Fig. 12, the

direction of discharge is reversed without changingthe speed or direction of rotation of the cylinder body. In this disclosure, the plungers are collar into tight forced inward and have their discharge stroke during the lower half of the revolution and are drawn out and have their suction stroke during the upper half. It can readily be seen that the distance the floating ring is eccentric with 11,, to the cylinder body, determines the amount of e the stroke, and hence, the volume of the di.-.

discharge pump, it is to be understood that any '20 form of hydraulic or fluid pump may be used which has a variable capacity and reversible discharge.

Referring more particularly to the disclosure in Figs. 13, 14 and 15, the numeral 1i refers to the oil well casing upon which is mounted the casing head 12, and in which is positioned the oil well tubing 13, which at the bottom of the well is connected to a motor cylinder commonly called the working barrel, which contains the plunger and valves for pumping the oil up through the tubing and permitting its discharge through the pipe T 1d. ,The tubing 13 is suspended on the collar 15 which rests upon an adjustable ring 16. The casing head 12 is provided with a packing 11 for sealing the space inside the casing from the atmosphere. The pump rod 18 actuates the plunger in the bottom of the well, this rod passing through the tubing 13 and is connected above the stumng box 19 to a driving means.

The cylinder 13 of the double acting hydraulic motor is provided with a piston 85 which imparts movement to the pump plunger in the bottom of the well through the medium of the pump rod 18. The motor cylinder 13 is mounted on 43 the casing head 12 in any suitable manner and at its ends is provided with the manifolds M and I5. In the embodiment selected to illustrate the invention, standards 82 are provided, extending from the collar 83 on the casing head to the base 5-0 of the manifold M. The cylinder is is provided with a piston and the piston rod 84 passing through the end covers 85 and 85 of the manifolds and stuffing boxes 81 and 88. I

For convenient adjustment of the total active length of thepump' rod 18, a portion 89 of this rod adjacent the upper end thereof is threaded and adapted to be received within an internally threaded portion 90 in the piston 80. The upper end of the piston rod 84 is split and provided with C tapered threads 9| to receive a lock nut 92, facilitating the piston rod being tightly connected to the pump rod 18 by means of a threaded and split sleeve 93 whereby to prevent the piston 80 from turning on the rod .18 after adjustment has C5 been made. To permit convenient applir ation of a wrench or other tool for turning the piston around the rod 18, the piston rod 84 is fitted at its upper end with a split collar 94 which is held by means of a key 95 in addition to the clamp- 70 ing action of a screw 96 adapted to draw the split clamping engagement. The threaded end of the pump rod 18 isprovided at its upper end with a split nut or collar 91 which is clamped together by means of a bolt 98, the 75 the conduits I2 for supplying fluid thereto, while the lower conduit II connects with the manifold I4. These manifolds are designed to serve as a safety and stop mechanism in case the cylinder on any occasion should be overcharged with fluid in one direction or the other.

.The manifolds likewise automatically aid in starting and controlling the stroke. Fluid entering the manifolds through the port I I, Fig. 14, from the conduit II, will pass therethrough into the bottom, of the cylinder I3 whereby to raise the piston 80 and the piston rod 84, along with the pump rod 18. The piston-80 at the end of this maximum working stroke, uncovers a port I08 which allows theexcess incoming fluid to be bypassed through a valve I03. 'A spring I04 normally holds this'valve in seatingengagement so as to prevent anyincoming fluid through the conduits II and port IOI from passing through the by-pass I05, and then through the valve. This construction provides a safety means whereby the cylinder cannot be overcharged. The valve I03 seats within a bushing I06, the valve construction being removable through a threaded closure I01. As the valves in each manifold are identical in construction, the same reference characters are applied thereto.

Each end of the cylinder is provided with a bypass in connection with inlet and outlet ports, the construction being the same, but the by-passes being reversed. For purpose of draining the-system completely of air, drain plugs and air vent I03, I09, and I I0 are provided.

The stufling boxes 81 and 88 are each provided with scraper rings II I each provided with a threaded connection II2 to which may be connected conduits or drain pipes for draining or leading the fluid which might leak through back into a supply storage contained in the housing of the pump I0 orconnected therewith. The closure or head I I3 for each of the stufling boxes is connected to the end covers 35 and 06 by means of threaded bolts or the like I I4.

The piston is shown as provided with a plurality of rings H5, and in the space between the piston and the cylinder covers is provided a spring III; which acts as a resilient stop for the piston so as to prevent any shock thereto at the end of the stroke;'

In the operation of the constructions which have so far been disclosed,.it is advisable before starting the pump I0 to turn the control screw 45 by means of'the hand wheel 46 so as to move the fork 31 to its lowest position, corresponding to zero delivery on'the pump I0. Thereafter, by turning the hand wheel 46, the stroke of the rod 42 will be gradually increased which in turn increases the stroke of the control or cross bar 59. This in turn adjusts theposition of the floating ring 68 so that the same may deliver any capacity of fluid that is desired at everyinstant during the cycle of its operation. The prime mover which operates the pump I0 also rotates the shaft I8 carrying the single or double cam arrangement, which cam or cams through lever rod 3I and lever 32, reciprocates the rod 42 con nected to the pump. The length of the stroke is controlled by means of the fork 31 and its adjusting screw, whilethe desired acceleration and deceleration on the piston 80 is accomplished by means of the cam construction and contour.

cation of thiscross head will throw the floating By reason of the above construction and arrangement the supply pump I0 will delivera flow of fluid under pressure flrst in one direction and then in the other direction, through the conduits II and I2. Now supposing that the piston 80 is 5 in its lowest position resting against the spring I I6 and the pump I0 starts to deliver fluid through theconduit II. The fluid will act on the'under 'side, of the piston 80 causing it to move upwardly until the flow is reversed. In the meantime the 10 delivery from pump ID has increased by the operator turning the screw 45 upward so as to raise the fulcrum 36 in the fork 31. Thus the volume delivered on the downward stroke is greater than it was on the preceding upward stroke. The -difference in amount of fluid is by-passed through the valve I03 to the suction line. When flow is again reversed, the piston will move'higher up in the cylinder than it did on the previous upward stroke. By turning the hand wheel successively,

the piston will come higher up in the cylinder for each stroke until the upper by-pass valve I03 of the cam. When the fulcrum 36 is at its uppermost position on the head 32 of the lever 32, a

maximum reciprocation is transmitted by the lever to the rod 42. When the fulcrum 36 is lowered adjacent to or in alignment with the pivot 40 of the block 39, no reciprocation of the connecting or lever rod 3I and lever 32 is transmitted to the rod 42 and the stroke of the pump is at zero.

In Figs. 16 and l'lare disclosed alternate constructions in which the main pump is provided with control and balancing means, as well as with a stroke limiting device. The means for shifting the floating ring of the pump off-center, which in the previous embodiment was done mechanically,

in this alternate construction, it is done hydrauli- 45 cally through the medium of a servo or auxiliary pump I I1. This servo ,pump construction is similar to that of the main pump, although it is to be understood that any type of variable capacity pump may be provided as desired. I Referring more particularly to Fig. 16 of the drawings, the casing II8 houses the shaft II9 upon which is-mounted a cam I20. On the hub I2I are mounted blocks I 22, one on each side of the cam. The bifurcated cam follower 124 is slidably mounted on the blocks I22. A roller I25 is rotatably mounted within the cam follower I24, and is at all times in contact with the face i or circumference of the cam I20. The cam follower I24 is in turn connected to a lever 32, similar to the constructions disclosed in Fig. 7, of the drawings. Likewise, the fork 31, adjusting screw 45 and hand wheel 46 are similar to the previously described construction. The rod 42 is provided with a reduced portion I26 upon which is mounted a spring I21 seating between the shoulder I28 on the rod 42 and a cross arm I29 for holding the roller I25 in contact with the cam I20. The outer end of the rod 42 is connected to a cross head I30 similar in construction, to '0 the cross head 59 in the main pump. Reciproring of the servo pump into off-center or on-cen ter position depending on the stroke desired.

In Fig. 17 is disclosed a somewhat similar con- .75

struction of controlling device and cam arrangement as shown in Fig. '16, but disclosing the parts in rearranged position so that the controlling device and hand wheel are at the rear of the unit. In thisv form, the rod I3I which is reciprocated, is mounted within bearing sleeves I32 and I33, and atjits outer end is connected at I34 to a lever arm I35 pivoted at I35 to the casing or housing I31 of the cam device. The lever I35 is bifurcated and the sides thereof provided with slots I38 for receiving a head I39 on the rod I3I. Likewise the lever is provided with slots III] for receiving a head MI on a rod I62 which is connected to a cross head I63, similar in construction to the cross-head 59 of the pump disclosed in Fig. 10.

This rod M2 is adapted to be reciprocated by the lever I35 and in order to return the rod after it has reachd the end of its stroke, the invention comprehends the provision of a tension spring I44 for accomplishing this result, the function being the same as the compression spring I21 in Fig. 16.

. By proper adjustment of the hand wheel 46 and screw 55 so as to shift the fulcrum of the fork 31, any desired stroke may be secured on the servo or auxiliary pump II1. Connected to the auxiliary pump III are provided conduits I65 and I66 through which is discharged the fluid from the pump in opposite directions during each cycle of operation. The conduits Hi5 and ISIS-are connected to the opposite ends of a control cylinder I61, Fig. 16, at one side of the main pumpIIl. Connected to the conduits I 55' and I 46 are pipes or lines I68 and I49, Fig. 17, leading to opposite ends of a balancing cylinder 155 for the purpose of counteracting such forces inside the pump which can practically be balanced with the pressure in the fluid lines. This balancing structure comprises a housing or casing I5I adapted to be attached to a side of the auxiliary pump I I1, the cylinder being provided with a piston I52 having a rod I53 attached to a cross head I54, also similar in construction to the cross head 59 of the pump shown in Fig. 10. At each end of the cylinder are provided threaded closures I55 and I56 so as to make an air and liquid tight joint. Fluid passing through the pipes or lines I68 and I 49 flows in alternate directions in each cycle, so

- that the fluid passing down through the pipe M8 from the conduit I45, will force the piston I42 into the position shown in Fig. 17, while at the next instance when the flow is reversed, the fluid will flow through the conduit I69 while the fluid to the left of the piston I52 will flow outwardly through the pipe M8 into the conduit or line I45.

Again referring more particularly to the disclosure in Fig. 16 in which is shown the complete main and auxiliary pump unit, fluid flowing into the control cylinder I51 through the pipe or conduit I 65, will force. the piston I51 to the left. The piston rod I56 being connected to the cross previously described operation, the pump was discharging, then during this part of the cycle, will be the suction stroke of the pump. In this construction, the control cylinder performs-hydraulically the function of shifting the floating ring of, the pump III off-center, whereby to provide the length of stroke of this pump, which operation was performed in the construction disclosed in Figs. 1 to 4 inclusive, by mechanical means. Should it be found that there is a greater 5 flow of fluid on one side of the piston than on the other, this excess fluid is by-passed through spring-pressed valves I59 as shown in Fig. 21, which permit the flow of fluid in but one direction. Any fluid so by-passed is drained through 10 a pipe I60 to a supply reservoir IBI. In order to replenish the supply of fluid, pipes I62 and I63 are provided, each pipe being furnished with a replenishing valve 0: as shown in Fig. 22, so as to prevent drainage of fluid from the supply line during the normal'operation of the unit. The replenishing valves are plain check valves similar to those shown in pipes I62 and I63, which permit a flow of oil from the reservoir I6I to the pump, but preventing any oil going back to the 20 reservoir from the pressure line.

The conduits I I and I 2-of the main pump I 6 may likewise be provided with replenishing pipes I62 and I63 having replenishing valves to permit a flow from the reservoir to the main conduits.

' Connected to the side of the main pump Ill opposite the control cylinder I41, is a balancing cylinder I65 and a stroke limiting device I65. This balancing cylinder is provided with a piston I66, the opposite ends of the cylinder. being providedwith supply pipes or lines I61 and I68 con necting with the main supply conduits I I and I2 of the pump I0. It is to be understood that the -flow of fluid and the pressurein the conduits I61 85 I 11! which are associated with the floating ring in the pump I0. Thus, any movement of the piston I66 is transmitted through these rods to the floating ring in the cylinder of the pump for to the purpose of counteracting or balancing forces inside of the pump, and to help in the shifting of the floating ring. In order to limitthe stroke of the piston I51 in the control cylinder, the invention comprehends a stroke limiting mechanism which may be shifted by the operator so as to adjust the stroke. This stroke limiting device comprises a threaded member I12 adapted to be rotatedby a hand wheel I12. The member I12 is provided with threaded sections I13 and I14, one provided with left hand and the other with right hand threads, the function of which is to draw the cross arms I15 and I16 toward one another, or when the hand wheel is operated in the other direction to shift the position of the cross to arms so that they are threaded away from one another, whereby to increase the gap between them. The gap or distance between these cross arms I 15 and I16 determines the stroke of the piston I51 as well as the piston I66 for the reason 65 that the cross head I10 operates therebetween and is thus limited in its movement. It is to be understood that both the control piston I51 and thebalancing piston I66 are connected by the cross heads 59 and I10, and the tie rods I1I so 70 I that the same movement is imparted to both pistons. The cross arms I15 and I15 along. with the cross arm I11 are mounted on rods I18 which are connected to the balancing cylinder, the cross arm I 11 being fixedly mounted thereon, while the 7s brace members I 2,027,104 cross arms I15 and I16 must necessarily be loose thereon so as to permit their relative adjustment. The valves I59 are spring loaded relief valves set for a pressure higher than the ordinary working pressure in cylinder I41 When the cross head I10 is stopped against the cross arms I15 or I16, the pressure in cylinder I41 increases and valve I59 opens until the flow is reversed and this side of the cylinder I41 becomes the suction side.

The stroke limiting device is to prevent accumulation of error in the control cylinder where there is any inaccuracy in delivery of fluid by reason of inaccuracy in the cam. For instance should a greater volume of fluid be delivered through conduit I45. Fig. 16 than through conduit I46, the piston crosshead I10 stops against'cross arm I15. The still incoming fluid through conduit I45 is then bypassed to the oil supply IGI, through relief valve I59 and pipe I60. In the same way is corrected any error in the volume of through conduit I46.

In Fig. 19 is shown a plan or lay-out of the unit or assembly when the servo or auigiliary pump as well as the control and balancing cylinder and stroke limiting device, are employed. An electric motor or other prime mover I18 drives through a flexible coupling I19, the shaft 9 of the main pump I0- This motor likewise through sprockets or other driving means I and I8I, drives a speed reduction mechanism I82 which in turn drives the cam shaft in the cam housing I31. The servo or auxiliary pump I I1 is likewise driven through suitable drive mechanism including a flexible coupling I83. By this construction, the various rotating parts are driven in timed relation so as to provide a properly synchronized working relationship between the various parts making up the unit or equipment.

Referring again'to the complete oil well pumping unit-disclosed in Figs. 1 and 2, the supporting structure is made. shiftable so as to permit ready access to the various parts. In this arrangement,

the rest or support I84 carrying the beam I85 supporting the pulleys I86, cable I81 and counterweight I00, is shiftable upon the pivotal support ture is to disconnect the support 484 and its I89 and I90. I

- In Fig. 20 ,is disclosed an illustrative chart plotting the time and delivery during each cycle which includes the up and down stroke, it-being understood that the pump is of the reversible type having a; discharge and a suction stroke so as to reverse the flow of fluid through the cylinder I3. The chart discloses curves a and b plotted on coordinate axes, the vertical divisions denoting the delivery in gallons per minute on each of the up and down strokes, while the horizontal divisions denote the time consumed in each cycle of the working and suction or returning stroke. The curve a denotes the volume of-fluid delivered in every moment of the cycle from the main pump I0, and curve b denotes the quantity of fluid delivered from the servo pump in every moment during the cycle when the main pump performs in accordance with curve a. The curves a and bare in vertical different scale, the delivery from the servo pump being only a few per cent of delivery from the main pump. Between the curves a and 1) exists also the relation that when curve a ma certainscale denotes the velocity of piston 80 in cylinder I3, curve b indicates the corresponding acceleration and deceleration of the piston 00.

and suction stroke.

I51 can only move until the fluid delivered I88. All that is necessary to shift this strucassociated with It is of course to be understood that these curves are but illustrative and velocity and acceleration within the stroke may be readily altered by varying the contour or face of the cam to give the d 'ired upstroke and downstroke, or discharge Likewise, the capacity may be varied at will.

From the above description and the disclosure in the drawings,,it will be invention comprehends, equipment is suitably adapted for use in other fields than in the oil industry The same is admirably adap'ted foruse in milling machines or planers, punch presses, screw machines, and vari- V ous other machines and devices-where it is-desired to operate some mechanism or tool in a positive cyclic movement.

readily seen that the and that the unit and.

.In the oil industry, the invention serves a long felt need and eliminates to a great extent the frequent shutdowns and delays caused by break-.

age of the pumping rod due to the enormous stresses and strains under which the same has to operate in combination Wlth the pumping device synchronized with the pump for operating the piston in a positive cyclic movement, said means we claim:

including a system of levers associated with the pump for controlling piston, and means for the length of stroke of the shifting thefulcrum of said levers whereby to vary the capacity and flow from the pump and the stroke of the piston between zero and maximum position.

2. In an hydraulic transmission system including a variable capacity pump provided with stroke controlling means, a cylinder provided with a re ciprocating piston, automatic means for imparting to the piston a positive cyclic movement and including a cam and a parting movement of the cam to the controlling means of the pump, and means for shifting the position-of the fulcrum of said levers whereby to increase or decrease the stroke of the pump.

3. In an hydraulic power transmission system, a motor, a variable capacity pump for delivering fluid to said motor, cam actuated means operated in synchronism with the pump for controlling the rate and direction of discharge of said pump and imparting to the motor any desired positive cyclic movement, and means for controlling the stroke of said pump.

4. In an hydraulic power transmission system,

a motor, a variable capacity pump for delivering fluid to said motor, cam actuated means operated in synchronism with the pump for controlling the discharge therefrom and imparting to the motor any desired positive cyclic movement, means for controlling the stroke of said pump, and hydraulic means applied to said stroke controlling means for reducing the force required to operate the same.

, 5. Inan hydraulic power transmission system, a cylinder provided with a reciprocating piston,

; a pumpfor delivering fluid to the piston, means rotated in timed relation with the pump for controlling the capacity anddirection of flow from the pump and thereby controlling the movement of the piston in its cycle of operation, and means the pump for controlling the length of the stroke of said piston.

system of levers for ima 6-. In an hydraulic power transmission system,

a cylinder provided with a reciprocating piston, a

variable capacity pump for supplying fluid to said cylinder, means synchronized with the pump for controlling the stroke of the pump and thereby operating the piston in a positive cyclic movement, and a by-pass at each end of the cylinder adapted to be uncovered by the piston to exhaust any overcharge of fluid to the cylinder.

7. In an hydraulic device for oil well pumping. a cylinder'provided with a reciprocating piston, a variable capacity pump for supplying fluid to said cylinder, means operating in timed relation with the pump for controlling the capacity and discharge of the pump and operating the piston in a positive cyclic movement, and means for exhausting any overcharge of fluid in the cylinder..

- a cylinder provided with a reciprocating piston,

a variable capacity pump for supplying fluid to said cylinder, means operating in timed relation with the pump for controlling the discharge of the pump and operating the piston in a desired positive cyclic movement, and means including a cylinder and piston operable therein for balancing the frictional resistances caused by the hydraulic forces in said pump.

10. In an hydraulic power transmission system, a cylinder provided with a reciprocating piston, a variable capacitypump for supplying fluid to said cylinder for operating the piston, means -operating in synchronism with the pump for operating and controlling the stroke of the pump whereby to operate said piston in a positive cyclic movement, and means for limiting the movement of said controlling means.

11. In an hydraulic power transmission system, a cylinder provided .Wlth a reciprocating piston. a variable capacity pump for supplying fluid to said cylinder for operating the piston, and hydraulic means synchroniz'edwith the pump for controlling the discharge of the pump and for balancing the frictional resistances caused by the hydraulic forces in said pump.

12- In an hydraulic power transmission system, a control cylinder provided with a reciprocating piston, a variable capacity pump for supplying fluid to said cylinder for operating the piston, and means including a driven cam synchronized with the pump for controlling the capacity and direction of flow from the pump for imparting to the piston any desired positive cyclic movement.

13. In an hydraulic device for oil well pumping, a cylinderlprovided with a reciprocating piston, a variable capacity pump for delivering fluid to the cylinder to actuate the piston, and cam actuated means operated in synchronism with the pump for controlling the capacity and direction of flow from the pump for imparting to the piston a desired positive cyclic movement.

14. In an hydraulic power transmission system, a cylinder provided with a reciprocating piston, a variable capacity pump for delivering fluid to the cylinder to actuate the piston, and means synchronized with the pump for continuously imparting to the piston any desired positive cyclic movement.

15. In an hydraulic device for oil well pumping, a cylinder provided with a reciprocating piston, a variable capacity pump for delivering fluid to the cylinder to actuate the piston, and means synchronized with the pump for controlling the discharge therefrom and for imparting to the,

piston a working stroke of variable velocity and of longer duration than the return stroke.

16. In an hydraulic power transmission system,

a cylinder provided with a reciprocating piston,

a pump for delivering fluid to the piston, and cam actuated mechanism synchronized with the pump for varying and controlling the stroke of the pump and piston, the cam being so constructed and arranged that the Working and return strokes of the piston are of unequal duration and variable velocity.

18. In an hydraulic device for oil well pumping, a cylinder provided with a reciprocating piston, a pump for delivering fluid to the piston, and automatic working mechanism synchronized with the pump for varying the stroke of said pump between a positive maximum and a negative maximum output whereby to operate the piston in a positive cyclic movement. I

19. In an hydraulic device for oil well pump: ing, a cylinder provided with a reciprocating piston, a pump for delivering fluid to the piston, and means operated in synchronism with the pump for actuating and controlling the length' of the stroke and capacity of the pump whereby to impart to the piston a desired positive cyclic movement. v

20. In an hydraulic device for oil well pumping, a cylinder provided with a reciprocating piston, a pump for delivering fluid to the piston, means associated with the pump for controlling the length of the stroke of the piston, and means operated in timed relation with the pump for controlling the stroke and capacity of the pump and the continuous cyclic operation of the piston.

21. In. an hydraulic device for oil well pumping, a cylinder provided with a reciprocating piston, a variable capacity pump for supplying fluid to said cylinder for operating the piston, and cam actuated means operated in timed relation with the pump for determining the stroke of the pump whereby to operate the piston in a positive cyclic movement.

22. In an hydraulic power transmission system, a'cylinder provided with a reciprocating piston, a variable capacity pump for supplying fluid to said cylinder for operating the piston, and cam actuated mechanism operated in synchronism with the pump for controlling and determining the stroke of the pump whereby to operate the piston in a positive cyclic movement.

23. In an hydraulic power transmission system, a cylinder provided with a reciprocating piston, a variable capacity pump for supplying fluid to said cylinder for operating the piston, means operated in timed relation with the pump for actuating the pump and determining the stroke thereof, and means associated with said first named 1 2,027,104 means for adjusting and controlling the lengths! 7 stroke of said piston.

24. In an hydraulic power transmission system, a cylinder provided with a reciprocating piston,

a variable capacity pump for supplying fluid to said cylinder for operating the piston, cam actuated means operated in synchronism with the pump for controlling the discharge from the pump and actuating the piston in any positive cyclic movement, and means for changing the stroke said piston.

25. In an hydraulic power transmission system.

" a cylinder provided with a reciprocating piston, a variable capacity pump for supplying fluid to said cylinder !or operating the piston, automatic means synchronized with the pump for controlling the stroke of the pump and imparting to the piston a desired positive cyclic movement, andmeans associated with the cylinder for operating the piston in synchronism with the flow oi fluid from the pump.

.26. In an hydraulic power transmission system. a cylinder provided with a reciprocating piston. a variable capacity pump for supplying fluid to said cylinderior opera-ting the piston, cam actuated means synchronized with said pump for controlling the discharge of the pump and operating thepiston in a positive cyclic movement, and means associated with the cylinder for preventing the cylinder at either end of the piston from being overcharged with fluid from the pump.

2'2. In an hydraulic power transmission system. a cylinder provided with a reciprocating piston, a variable capacity pump for supplying fluid to said cylinder for operating the. piston, means rotated in timed relation with the pump for controlling the discharge and direction oi flow from the pump and operating the piston in a positive cyclic movement, and a spring seating within said cylinder for intercepting the piston so as to prevent sudden stops in the movement of the piston or shocks imposed thereon.

28. In an hydraulic power transmission system, a cylinder provided with a reciprocating piston, a pump for delivering fluid to the piston. a cam rotated in timed relation with the pump tor controlling the discharge of the pump and imparting to the piston a desired cyclic movement, and

mechanism for controlling the length of stroke of the piston.

29. In an hydraulic power ton system. a cylinder provided with a reciprocating piston. a variable capacity pump for supplying mud. to

said cylinder, a cam rotating in synchronism with the pump for controlling the rate and direction of discharge of the pump and operating the piston in a positive cyclic movement. and means in the system for exhausting any overcharge oi fluid in the system.

80. In an hydraulic power transmission system, a cylinder provided'with a reciprocating piston. a variable capacity pump for supplying fluid to said cylinder for operating the piston, and-means for controlling the capacity and flow from the pump, said means including a second variable capacity and reversible discharge pump and cam the discharge of the pump and im mechanism operated in timed relation with the first mentioned pump for actuating said second pump.

31. In an hydraulic power transmission system, a variable capacity pump for supplying fluid under pressure, hydraulic means for controlling the stroke of said pump, said means including a cylinder and piston operable therein, and means also including a cylinderand piston operable therein and actuated by fluid under pressure from said 1 system for balancing the reaction forces on the pump controlling means. I 32. In an hydraulic transmission system, a cylinder provided with a reciprocating piston, a variable capacity pump for supplying fluid to said cylinder, means associated with the pump tor opcrating the piston in a positive cyclic movement, a control cylinder for controlling the stroke of the pump and provided with an hydraulically operated pisto mechanism for limiting the stroke ot the pump. means for supplyin fluid under pressure to said control cylinder in a determined quantity for each time element during the cycle, and a by-pass for any surplus fluid supplied to said control cylinder.

33. In an hydraulic transmission system, a variable capacity pump for supplying fluid under pressure, hydraulic means "for automatically changing the stroke of said pump in any r p ated cyclic movement, means for limiting said stroke. and means for by-passing any surplus fluid supplied to said controlling means. 1

I 34. In an hydraulic power transmission system, a control cylinder provided with a reciprocating piston, a variable capacity pump for supplying g fluid to said cylinder for operating the piston. means including a cam rotated in synchronism with the pump for controlling the capacity and direction of flow from the pump for imparti l to the piston any desired positive cyclic movement, 49

ton, a variable capacity pump delivering fluidto the cylinder to actuate thepiston. and means ineluding a cam rotated in timed relation with the pump for controlling the discharge from the pump and imparting to the piston aw desired positive cyclic movement.

36. In an hydraulic power transmission system, a motor, a variable capacity pump for delivering fluid to said motor. and cam actuated means operated in synchronlsm with the pump for controlling the capacity and discharge of the pump and imparting to the motor any desired positive cyclic movement.

37. In an hydraulic power transmission system. amotor', a variable capacitypump for delivering fluid to said motor. cam actuated meansopetatsd in synchronism with the pump for controlling go parting to the ,motor anydesired positive cyclic movement, hy-

draulic means for controlling the stroke of said pump, and means for limltini said stroke.

MAR'HN KAI-IR. .5

JOHN 8. BABE. 

